Physics 545 



Doctor Magowan shows that at a very early period the Chinese 

 possessed time-keeping devices of considerable complexity, 

 and that the subject of time division and measurement re- 

 ceived much attention at their hands many centuries before 

 the Christian Era. 



Professor Harkness, in his presidential address before the 

 Philosophical Society of Washington, has given an interesting 

 study of the " Progress of Science as Exemplified in the Art 

 of Weighing and Measuring," and a reprint of it appears in 

 the Report for 1888. It contains much matter of historical 

 value, especially the carefully prepared appendixes showing 

 the principal comparisons of early English and other impor- 

 tant standards of lenorth and mass. 



The Smithsonian Report for 1893 contains an article on 

 "Fundamental Units of Measure," by T. C. Mendenhall, be- 

 ing a reprint from the Transaciiojis of the American Society 

 of Civil Engi7teers, of a paper read before the International 

 Engineering Congress of the Columbian Exposition. This is 

 a brief sketch of the general principles of metrology, followed 

 by an account of the origin of the English system of weights 

 and measures, and a statement in some detail of the actual con- 

 dition of the question of " standards " in the United States. 

 The official announcement by the Secretary of the Treasury 

 is there given of the adoption of the national prototype meter 

 No, 27 and kilogram No. 20 as fundamental standards of 

 length and mass, the yard and pound to be defined in the 

 future in terms of these units. The article concludes with 

 the formal announcement of the Superintendent of Standard 

 Weights and Measures, with the approval of the Secretary 

 of the Treasury, of the adoption of the units of electrical 

 measure, with their definitions as formulated and agreed 

 upon by the International Electrical Congress held in Chi- 

 cago in 1S93. 



